[mythtv-users] Best place to insert a CATV amp
mythtv at edsons.demon.nl
Fri Jan 26 22:45:59 UTC 2007
Brian Wood wrote:
>On Jan 26, 2007, at 3:17 PM, Rudy Zijlstra wrote:
>>>I cannot seem to find a good answer anywhere on this, so maybe
>>>someone here can help.
>>>Q: In a line with several splits, where is the best place to add
>>>I just hooked up my newly recreated mythtv backend. It has a
>>>PVR350 and a PVR500 in it. At first I was getting pretty icky
>>>picture, so I hooked up a powered amp and it got better. But not
>>>as good as it should.
>>>Pretty much my arangement is like so: Sorry for it being
>>>confusing, but I am unsure how to portay it. I've noted where I
>>>have considered putting it by inserting (option #). I can also
>>>get an amp with multiple outputs which may be the way to go.
>>>I *believe* I have near perfect cable signal coming in (not too
>>>strong / not too weak) - but then again they did not seem to be
>>>the sharpest of people...
>>>-> RUNS TO HOUSE
>>>-> 2 WAY SPLITTER -> TV | CABLE MODEM
>>>TV: (Option 1)
>>>-> 4 WAY SPLITTER
>>>4 WAY SPLITTER:
>>>-> TV -> (Option 2) -> 3 WAY SPLITTER
>>>3 WAY SPLITTER:
>>>-> (Option 3) -> PVR500 (Which has a 2 WAY built in I believe)
>>>Basically the question comes down to is it better to boost the
>>>signal higher and let it drop down as it goes through, or let it
>>>drop down, then boost it.
>>>As I understand it, you get poor quality when it is too high or
>>>too low... so should I work out the drops so it always stays as
>>>close to the starting point?
>>If you put an 8dB amp before the 4-way it should work. If signal is
>>at PVR at that point, you can still increase that 8dB to 16dB without
>Be careful about talking about signal level as if it were a single
>channel. When you state a level is that the highest or the lowest of
>the 50+ channels?, or an average? Is this the highest the cable
>company ever sends you or the lowest? The levels vary all over the
>place both in frequency and with time.
>That's why I wanted to try and give at least a brief explanation,to
>show that talking about levels with a single number is meaningless
Which for you poor US citizens is quit true, thanks to the prevalance of
In Netherlands, and most EU countries (parts of UK being excluded) we
are lucky enough to have underground feeds, and i happen to know that
the cable ops try their best to have all signals entering the house at
the same level (same type at same level), no matter the frequency.
Under that assumption the simplification holds...
Still, i have a tendency to take a spectrum analyzer from work when i
really want to play with signal amplification in my home.... That way i
know what i am doing at the different frequencies.
- and as you probably noted, the numbers were taken to compensate for
the most likely signal loss incurred by the splitters.
More information about the mythtv-users